Engines, and in particular turbine engines, include a number of fluids which are consumable in that they deteriorate with time and operational conditions. It is also true that various components within an engine wear and debris from that wearing process become entrained within the fluids. A number of techniques have been devised for elucidating the condition of lubricants, coolants and other consumables within an engine along with determination of particulate debris within fluid flow circulated within an engine. One example of such an approach is using nuclear magnetic resonance (NMR) and one method is outlined in U.K. patent application no. 0022587. In short, NMR signals are presented to the fluidic flow such that variations in the fluid as well as debris content are detected by response signal frequency shift and broadening. These frequency shifts and response signal provide indications of the fluidic flow condition in terms of constituent component fluids as well as deterioration in those components through combustion and particulate content reflective of wear debris. This technique is non intrusive in that the fluid flow can be analysed in situ by locating appropriate sensors around a conduit for that fluid flow. Nevertheless, analysis generally takes several minutes and so is difficult to utilise with respect to closed loop control of engine function.
Some engine purchase or management schemes closely tie payment to the period of time for which the engine is powered up with charging on a unitary basis. In such circumstances if the engine is not properly operated such calculations with regard to costs of operating of the engine are significantly prejudiced. In short, if incorrect consumable fluids are used the engine will not be operating in accordance with manufacturer's specifications and so the engine will require earlier and probably remedial servicing. Such servicing costs and remedial action will fall upon the leaser of the engine rather than the operator who clearly has an incentive to use inferior and therefore probably cheaper consumable fluids etc. In such circumstances a means for verifying appropriate operation of the engine is required.